Severe childhood autosomal recessive muscular dystrophy (SCARMD) is a disease which is prevalent in North Africa. This progressive muscular dystrophy shares several clinical features with Duchenne's muscular dystrophy (DMD) including, for example, mode of onset, rapid progression, hypertrophy of calves and extremely high serum creatine kinase levels during the initial stages of the disease (see, e.g., Ben Hamida et al., J. Neurol Sci. 107: 60-64 (1992)).
It has been demonstrated that Duchenne's muscular dystrophy is caused by a mutation or deletion which results in the absence of the dystrophin protein (Hoffman et al., Cell 51: 919-928 (1987)). Dystrophin has been shown to be associated with a large oligomeric complex of sarcolemmal glycoproteins (see, e.g., Ervasti and Campbell, Cell 66: 1121-1131 (1991)). The dystrophin-glycoprotein complex has been proposed to span the sarcolemma and provide a linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. In DMD, the absence of dystrophin leads to a great reduction in all of the dystrophin-associated proteins. These observations have enabled, for example, the development of immunologically-based methods for the diagnosis of DMD.
In contrast to DMD, it has been reported that dystrophin and dystrophin-related protein (DRP), an autosomal homologue of dystrophin, are expressed normally in the skeletal muscle of individuals afflicted with SCARMD (see, e.g., Khurana et al., Neuromusc. Dis. 1: 185-194 (1991)). Thus, there is no teaching in the prior art which would enable the development of an immunologically-based method for diagnosing SCARMD, or other autosomal muscular dystrophies.